Physical quality of gluten-free doughs and fresh pasta made of amaranth.

Pasta is one of the most consumed foods in the world. Therefore, the development and investigation of the quality parameters of fresh gluten-free pasta made from amaranth was the subject of this study. For this purpose, different doughs (amaranth flour: water 1:2, 1:4, 1:6, 1:8, 1:10) were heat-treated and sodium alginate (1.0 and 1.5%) was added. The pasta was produced by extrusion into a 0.1 M calcium L-lactate pentahydrate-containing bath. Both the dough and the pasta were examined. The doughs for its viscosity properties, water content, and color and the pasta for its firmness, color, water content, water absorption, cooking loss, and swelling index. The pasta was cooked for 5, 10, and 15 min for the cooking quality study. A higher alginate content of 1.5% and a higher proportion of amaranth flour resulted in a significant difference in color, water content, and shear-dependent viscosity of the dough (p < .001). It was also found that both doughs with amaranth flour-water content of 1:2 and 1:10 had significant effects on processing properties and pasta quality, especially on firmness, swelling index, and cooking loss. For the doughs with a 1:2 ratio, the high flour content resulted in very soft pasta, and for the doughs with a 1:10 ratio, the high-water content resulted in very firm pasta with a smooth, watery surface. Overall, cooking loss, swelling index, and water absorption were low for the pasta with 1.5% alginate. Even with cooking times of 15 min, the pasta retained its shape.

The microstructure of the starch from the underutilized seed of jaboticaba (Plinia cauliflora).

This work presents a starch extracted from jaboticaba seeds. The extraction yielded 22.65 ± 0.63% of a slightly beige powder (a* 1.92 ± 0.03, b* 10.82 ± 0.17 and L* 92.27 ± 0.24). The starch presented low protein content (1.19% ± 0.11) and phenolic compounds (0.58 ± 0.02 GAE. g) as contaminants. The starch granules showed small, smooth, irregular shapes and sizes between 6.1 and 9.6 µm. The starch presented a high content of amylose (34.50%±0.90) and a predominance of intermediate chain length (B1-chains 51%), followed by A-chains (26%) in the amylopectin. The SEC-MALS-DRI showed the starch had a low molecular weight (5.3·106 g·mol-1) and amylose/amylopectin content compatible with a Cc-type starch, confirmed in the X-ray diffractogram. Thermal studies showed a low onset temperature (T0 = 66.4 ± 0.46 °C) and gelatinization enthalpy (ΔH = 9.1 ± 1.19 J g-1) but a high-temperature range (ΔT = 14.1 ± 0.52 °C). The jaboticaba starch proved to be a promising material for food and non-food applications.

An Attempt to Relate Oleogel Properties to Wax Ester Chemical Structures.

Wax esters are considered to have a dominant contribution in the gelling properties of wax-based oleogels. To understand their gelling behavior, oleogels of seven different wax esters (total carbon number from 30 to 46; c = 10% [m/m]) in medium-chain triglycerides oil were characterized. Scanning electron microscopy revealed that wax esters crystallize in rhombic platelets with a thickness of 80 to 115 monomolecular layers. Bright field microscopy showed that the regularity and face length of the crystals increased with the total carbon number and molecular symmetry of the respective wax ester. Oscillatory rheology was used to characterize the gel rigidity (Gmax*). Here, wax ester oleogels with smaller total carbon numbers yielded higher Gmax* values than those of wax esters with higher total carbon numbers. The gel rigidity (Gmax*) inversely correlated with the crystal face length. Smaller and optically less well-defined platelets promoted higher gel rigidities. In the case of the microstructure of a specific oleogel composition being manipulated by a variation in the cooling rates (0.8; 5; 10 K/min), this relationship persisted. The information compiled in this manuscript further elucidates the crystallization behavior of wax esters in oleogels. This contributes to the understanding of the composition-structure-functionality relationship of wax-based oleogels supporting future food applications.

Wax based oleogels and their application in sponge cakes.

The use of high amounts of saturated fatty acids mainly obtained from tropical fats and oils gains increasing rejection from consumers. Use of liquid plant based oils, however, does not deliver necessary functionalities. In this contribution, sunflower-(SFW), bees-wax (BW), ricebran wax (RBW) and a BW-wax mixture (BW : SFWh) were investigated as a potential alternative fat phase in low-density bakery products. Since the food product matrix is composed of complex ingredients, key-functionalities (foam-stabilization, viscoelastic properties, and oil-binding) were first investigated for pure oleogels as oleofoams. It could be demonstrated that all waxes investigated were able to form oleofoams. The location of wax crystal aggregates, at the oil-air interface or in the bulk, was shown to be a significant factor regarding oil-binding and viscoelastic properties. However, it was not possible to transfer all findings made for the oleofoams to the ones made for the oleogel based sponge cakes. There, all oleogels showed improvement compared to the canola oil variant regarding oil-leaping and visual appearance (volume). Sensory evaluation attested satisfactory results for all wax-based oleogel applications. This contribution aims to deliver novel findings for wax-based oleogels as oleofoams as well as an alternative fat phase in low-density bakery products. The gathered results aim to enable a target-oriented characterization of oleogel applications and hence facilitate future use to deliver beneficial products to the market.

Effect of pre-swelling and freezing/thawing cycles on the structure of molecular, morphological, and functional properties of potato starch.

This study aimed to investigate the effect of pre-swelling at 55°C for 1 hr followed by freezing-thawing cycles (PFTCs), and freezing-thawing cycles (FTCs) in the starch granules to improve the freeze-thaw stability and evaluate its impact on the molecular, morphological, and functional properties of potato starch (PS). FTCs at 1 cycle and 7 cycles were applied for both treated PS. Microscopical structure, thermal, molecular, and functional properties (i.e., swelling power, solubility, shear viscosity, and gel strength) were comprehensively analyzed. In terms of granule structures, treated PS by FTC showed a slightly affected on the surface of starch granules, while treating PS by PFTC showed an affected in the form of small cracks and holes in the outer surface of starch granules. The gelatinization enthalpy (∆Hgel ) values decreased in the treated PS compared with the native. Thus, decreasing was systemically increased with the number of applied cycles from 1- to 7-cycle. The viscosity of treated PS decreased systematically with molecular degradation or the physical modification, with remarkable reduction, particularly at a higher shear rate (150°C). Treated PS by FTC showed a clear difference (p ≤ .05) in gel values compared with the native at disintegration temperature 115°C. Finally, the degradation of the molecular properties showed significant differences between the native and treated PS either by the FTC or PFTC in molecular weight of starch and amylose without debranching and after debranching by pullulanase enzyme. PRACTICAL APPLICATIONS: Freezing is one of the standard preservation methods used for ready-to-eat products. When this type of food's exposed to more freeze-thaw cycles, the phase separation will be increased due to the increase in retrogradation of amylopectin. To avoid such changes during frozen storage, native potato starch (PS) was modified using both pre-swelling followed by freezing-thawing cycles (PFTCs) and freezing-thawing cycles (FTCs) at 1- and 7-cycle to enhance starch properties, such as swelling power, solubility, shear viscosity, and gel strength. The findings of this study might add to the theoretical understanding of modified PS and act as a guideline for modified starch manufacturing.

Improving the nutritional profile of culinary products: oleogel-based bouillon cubes.

Structured fat phases are the basis of many consumer relevant properties of fat-containing foods. To realise a nutritional improvement - less saturated, more unsaturated fatty acids - edible oleogels could be remedy. The feasibility of traditional fat phases structured by oleogel in culinary products has been evaluated in this study. In this contribution the oleogel application in bouillon cubes as model system for culinary products is discussed. Three different gelators (sunflower wax (SFW), a mixture of ß-Sitosterol and γ-Oryzanol (SO) and ethylcellulose (EC)), at two concentration levels (5% and 10% (w/w)) each, were evaluated with respect to their physical properties, in the food matrix and application. The application of pure and structured canola oil (CO) was benchmarked against the reference, palm fat (PO). The assessment of the prototypes covered attempts to correlate the physicochemical analyses and sensory data. Organoleptic and analytical studies covered storage stability (up to 6 months) monitoring texture, color and fat oxidation. The results indicate that the substitution of palm fat by oleogel is essentially possible. The characteristics of the bouillon cubes are tuneable by gelator choice and inclusion level. Most importantly, the data show that the anticipated risk of intolerable effects of oxidation during shelf life is limited if antioxidants are used.

Oleogels-Their Applicability and Methods of Characterization.

Oleogels or, more precisely, non-triglyceride structured lipid phases have been researched excessively in the last decade. Yet, no comprehensive knowledge base has emerged, allowing technology elevation from the laboratory bench into the industrial food application. That is partly due to insufficient characterization of the structuring systems studied. Examining a single composition decided upon by arbitrary methods does not stimulate progress in the research and technology area. A framework that gives much better guidance to product applications can easily be derived. For example, the incremental structure contribution concept is advocated as a parameter to compare the potency of structuring systems. These can straightforwardly be determined by combining solubility data and structural measurements in the recommended manner. The current method to determine the oil-binding capacity suffers from reproducibility and relevance. A newly developed method is suggested to overcome these shortcomings. The recommended new characterization of oleogels should contribute to a more comprehensive knowledge base necessary for product innovations.

The supporting effect of ultrasound on the acid hydrolysis of granular potato starch.

The modification of starch owing to acid-thinning (AT) is intensified by a concomitant ultrasound (US) treatment, but the specific effect of the US on molecular changes, and the respective contribution of the single impacts are still unknown. The present study investigates the supporting effect of the US via examination and comparison of the single modifications [general conditions: starch slurry (40 % w/w), 40 °C, stirring; US: gradation of amplitude (50 and 100 %), cycle (0.50 and 0.75) and sonication time (20 and 60 min); AT: 0.36 M HCl, reaction time of 4 h] with the corresponding US assisted AT modified starches (US-AT) in terms of granular, molecular and functional properties. The US induced essentially a molecular degradation (debranching) of the amylopectin (AP), whereas chain cleavage within the amylose (AM) wasn't excluded completely. Altogether, the US was estimated to be a separate and assisting modification rather than an AT accelerating component.

Acid hydrolysis of corn starch genotypes. I. Impact on morphological and molecular properties.

With respect of the partial molecular degradation of the starch polysaccharides, the impact of the acid-thinning process on the specific starch properties of two corn genotypes was investigated. A high amylose corn (HACS) and a waxy corn (WxCS) starch were hydrolyzed using HCl in the laboratory scale slurry process (40% w/w, 30 °C). The acid concentration (0.3, 0.6 and 0.9 M) as well as the hydrolysis time (4, 10 and 20 h) were graded systematically (experimental design) and the obtained modified starch genotypes characterized comprehensively. As revealed by scanning electron micoscopy (SEM), the supramolecular structure was preserved in general, and the carbohydrate solubilization was limited to about 2-3 %. Molecularly dispersed solutions were characterized by means of size exclusion chromatography-multi angle laser light scattering-differential refractive index detection (SEC-MALS-DRI). Both acid concentration and hydrolysis time reduced the molar mass (MM) of the starch [HACS: 4.4∙106 (native)…1.2∙106 g∙mol-1 (highest degree of degradation); WxCS: 49.7∙106 (native)…6.4∙106 g∙mol-1 (highest degree of degradation)], the amylose (AM) fraction as well as the amylopectin (AP) branch chain length systematically. Perceptible differences in dependence on starch variety were ascertained and discussed. The molecular properties of the investigated acid-thinned genotypes are selectively controllable with the hydrolysis process. The relationship between modification process, starch's molecular state, and resulting functional properties was examined in the second part of the study.

Effect of quality and origin of technical sucrose solutions on the inclusion of colourants into the sugar crystal matrix.

BACKGROUND: Due to the liberalisation of the European sugar market the pressure to improve factory utilisation is growing. Currently, beet and cane as sucrose sources are produced in isolation, according to geography. Co-production of sugar from beet and cane origin in one stream is a promising option. However, the knowledge base for production sugar is practically non-existent. This paper is part of our contribution to this field and specifically addresses effects of raw material quality. RESULTS: This framework formulated for the colouring of sugars crystallised from mixed syrups is also valid for different raw material qualities: raw cane sugars: colour values 1221 to 2505 IU, dextran levels 50 to 1200 mg kg-1 ; beet syrups: 1509 to 2058 IU. Co-crystallisation is the main colour incorporation mechanism. Colour due to liquid inclusion increases strongly at cane inclusion levels in excess of 60%. The prediction of final sugar colour based on characteristics of pure mixture constituents is verified and indicates significant differences to current recommendations. CONCLUSION: A first comprehensive description of the colour values in sugars produced from mixed cane and beet syrups is presented. Prediction of colour values from data on sugar colour of single sources marks a major contribution to future applications of co-production. © 2017 Society of Chemical Industry.

The Phase Behavior of γ-Oryzanol and ß-Sitosterol in Edible Oil.

The phase behavior of binary mixtures of γ-oryzanol and ß-sitosterol and ternary mixtures of γ-oryzanol and ß-sitosterol in sunflower oil was studied. Binary mixtures of γ-oryzanol and ß-sitosterol show double-eutectic behavior. Complex phase behavior with two intermediate mixed solid phases was derived from differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) data, in which a compound that consists of γ-oryzanol and ß-sitosterol molecules at a specific ratio can be formed. SAXS shows that the organization of γ-oryzanol and ß-sitosterol in the mixed phases is different from the structure of tubules in ternary systems. Ternary mixtures including sunflower oil do not show a sudden structural transition from the compound to a tubule, but a gradual transition occurs as γ-oryzanol and ß-sitosterol are diluted in edible oil. The same behavior is observed when melting binary mixtures of γ-oryzanol and ß-sitosterol at higher temperatures. This indicates the feasibility of having an organogelling agent in dynamic exchange between solid and liquid phase, which is an essential feature of triglyceride networks.

Stability of aqueous food grade fibrillar systems against pH change.

We report that the stability of an aqueous food grade fibril system upon pH change is affected by the presence of peptides that are formed during the process of fibril formation. We discuss several other relationships between food relevant properties and nano-scale characteristics, and compare these relationships for aqueous fibril systems to those of oil based fibril systems. In such fibril systems, dynamics, self-organisation, and sensitivity to external conditions, play an important role. These aspects are common to complex systems in general and define the future challenge in relating functional properties of food to molecular scale properties of their ingredients.

Elucidation of density profile of self-assembled sitosterol + oryzanol tubules with small-angle neutron scattering.

Small-angle neutron scattering (SANS) experiments have been performed on self-assembled tubules of sitosterol and oryzanol in triglyceride oils to investigate details of their structure. Alternative organic phases (deuterated and non-deuterated decane, limonene, castor oil and eugenol) were used to both vary the contrast with respect to the tubules and investigate the influence of solvent chemistry. The tubules were found to be composed of an inner and an outer shell containing the androsterol group of sitosterol or oryzanol and the ferulic acid moieties in the oryzanol molecule, respectively. While the inner shell has previously been detected in SAXS experiments, the outer shell was not discernible due to similar scattering length density with respect to the surrounding solvent for X-rays. By performing contrast variation SANS experiments, both for the solvent and structurant, a far more detailed description of the self-assembled system is obtainable. A model is introduced to fit the SANS data; we find that the dimensions of the inner shell agree quantitatively with the analysis performed in earlier SAXS data (radius of 39.4 +/- 5.6 angstroms for core and inner shell together, wall thickness of 15.1 +/- 5.5 angstroms). However, the newly revealed outer shell was found to be thinner than the inner shell (wall thickness 8.0 +/- 6.5 angstroms). The changes in the scattering patterns may be explained in terms of the contrast between the structurant and the organic phase and does not require any subtle indirect effects caused by the presence of water, other than water promoting the formation of sitosterol monohydrate in emulsions with aqueous phases with high water activity.

Organogel-emulsions with mixtures of ß-sitosterol and γ-oryzanol: influence of water activity and type of oil phase on gelling capability.

In this study, water-in-oil emulsions were prepared from water containing different salt concentrations dispersed in an oil phase containing a mixture of ß-sitosterol and γ-oryzanol. In pure oil, the ß-sitosterol and γ-oryzanol molecules self-assemble into tubular microstructures to produce a firm organogel. However, in the emulsion, the water molecules bind to the ß-sitosterol molecules, forming monohydrate crystals that hinder the formation of the tubules and resulting in a weaker emulsion-gel. Addition of salt to the water phase decreases the water activity, thereby suppressing the formation of sitosterol monohydrate crystals even after prolonged storage times (∼1 year). When the emulsions were prepared with less polar oils, the tubular microstructure was promoted, which significantly increased the firmness of the emulsion-gel. The main conclusion of this study is that the formation of oryzanol and sitosterol tubular microstructure in the emulsion can be promoted by reducing the water activity and/or by using oils of low polarity.

The Influence of Concentration and Temperature on the Formation of γ-Oryzanol + ß-Sitosterol Tubules in Edible Oil Organogels.

The gelation process of mixtures of γ-oryzanol and sitosterol structurants in sunflower oil was studied using light scattering, rheology, and micro-scanning calorimetry (Micro-DSC). The relation between temperature and the critical aggregation concentration (CAC) of tubule formation of γ-oryzanol and sitosterol was determined using these techniques. The temperature dependence of the CAC was used to estimate the binding energy and enthalpic and entropic contribution to the tubular formation process. The binding energy calculated at the corresponding temperatures and CACs were relatively low, in order of 2 RT (4.5 kJ mol(-1)), which is in accord with the reversibility of the tubular formation process. The formation of the tubules was associated with negative (exothermic) enthalpy change (ΔH(0)) compared with positive entropy term (-T ΔS(0) >0), indicating that the aggregation into tubules is an enthalpy-driven process. The oryzanol-sitosterol ratio affected the aggregation process; solutions with ratio of (60 oryzanol-40 sitosterol) started aggregation at higher temperature compared with other ratios.

Comprehensive two-dimensional liquid chromatography x gas chromatography: evaluation of the applicability for the analysis of edible oils and fats.

Edible fats and oils are complex mixtures containing a wide range of (classes of) compounds. The most important group of compounds are the triglycerides (triacylglycerides, TAGs). Because of the large number of possible fatty acid combinations, an enormous number of TAGs is possible. In the present feasibility study, the applicability of different modes of comprehensive two-dimensional LCXGC for detailed oil and fat analysis is evaluated. Comprehensive LCXGC was found to be an extremely powerful analytical method for the analysis of complex TAG samples. Using the new comprehensive set-ups, TAGs can be separated according to two independent parameters: carbon number vs. number of double bonds, or fatty acid composition vs. number of double bonds. The information content of comprehensive separations by far exceeds that of the current generation of analytical methods. The quantitative results of the separations show a good agreement with data obtained from standard analytical methods. The comprehensive methods studied can also be used for fingerprinting of oil samples, as well as for the analysis of target compounds or compound groups. Highly detailed separations of olive oil samples were obtained. Zooming in on one region of the chromatogram allowed reliable analysis of wax esters without interferences of sterol esters.